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Joe K · 04-23-2017, 11:01 AM

I use No. 3 with an accessory "leveler" strap to either front of engine (landed on crankshaft pulley) if no transmission, or rear of engine (landed on lip of U-joint spherical joint) if with transmission.

One of my mentors in engineering was advising of "yeah, I know a single bolt will hold a critical load but use 4 bolts if casual human evaluation is required before entry or use." His the classic "elevator" case where a potential passenger mentally "gauges" whether it is safe or not before they enter. And one designs not only for the load - but also to get past that "acceptance" level.

You design for "expectation."

Still, the motor WITH transmission only weighs 475 lbs. Spark plugs LAUGH at that load. The torque alone on many plugs involves "bolt stretch" many times 475 lbs. Which has to be exceeded before bolt failure. And if a bolt (including spark plugs) will survive torquing, then it will certainly survive the design load.

And the classic engineer aphorism applies.

"An engineer is a person who will do for $1 what any fool would do for $2."

Joe K

04-23-2017, 11:01 AM	#11
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Engine removel I use No. 3 with an accessory "leveler" strap to either front of engine (landed on crankshaft pulley) if no transmission, or rear of engine (landed on lip of U-joint spherical joint) if with transmission. One of my mentors in engineering was advising of "yeah, I know a single bolt will hold a critical load but use 4 bolts if casual human evaluation is required before entry or use." His the classic "elevator" case where a potential passenger mentally "gauges" whether it is safe or not before they enter. And one designs not only for the load - but also to get past that "acceptance" level. You design for "expectation." Still, the motor WITH transmission only weighs 475 lbs. Spark plugs LAUGH at that load. The torque alone on many plugs involves "bolt stretch" many times 475 lbs. Which has to be exceeded before bolt failure. And if a bolt (including spark plugs) will survive torquing, then it will certainly survive the design load. And the classic engineer aphorism applies. "An engineer is a person who will do for $1 what any fool would do for $2." Joe K __________________ Shudda kept the horse.